Objectives are to characterize metabolic patterns in species with varying propensities for adipose tissue and muscle development and to identify mechanisms which regulate tissue and cellular patterns of metabolite utilization. Metabolic profiles of animals predisposed to variations in cellular development will be investigated in a series of experiments. The first series is the characterization of enzyme patterns in several tissues to ascertain general changes in metabolic pathways. To complement the enzyme studies, a second series of experiments utilizing in vitro tracer techniques in isolated cells and tissue preparations will permit the determination of metabolite utilization and the identification of alterations in biochemical pathways. The final series of experiments will involve tests of hormone sensitivities in vivo and in vitro. Correlations between enzyme activities, tracer studies and hormone sensitivities will be compared changes observed in growth in growth and development.